1. Field of the Invention
The present invention relates to a focus-controlling apparatus that can adjust a focus with respect to a plurality of focus areas and also to a photographing apparatus that has the focus-controlling apparatus.
2. Description of the Related Art
In recent years, cameras have become more sophisticated in performance and function. More and more cameras are used, each incorporating an auto focus sensor capable of detecting the focusing states at many focus areas in the photographing viewfield.
Most cameras of this type can operate in two focusing modes. One mode is a so-called manual focusing mode, in which the user may operate a focus-adjusting mechanism after looking at the viewfinder image and confirming that the object is focused. The other mode is a so-called automatic focusing mode, in which an auto focus sensor detects the focusing state at every focus area and the camera sets the focus at a given focus area.
In the manual focusing mode, the user first observes the viewfinder image and then adjusts the focused state of the object image. In this case, the user can indeed roughly set the focus at a desired object, but he or she requires high skill to set the focus at the object accurately and correctly. Hence, unless the user is a skilled camera user or is accustomed to using the camera, the pictures he or she takes may be somewhat out of focus. That is, he or she may fail to take a good picture.
In the automatic focusing mode, a desired object can be indeed focused without fail, but a focus area different from the point at which the object desired by the user may be selected. In this case, the image of the desired object will be out of focus and the camera will fail to take a good picture.
To prevent the selection of a wrong focus area in the automatic focusing mode, various methods have been proposed, which enable the user to select a desired focus area, thereby to taking a good picture.
For example, the camera disclosed in Jpn. Pat. Appln. No. 1-288845 comprises a camera body and a view-selecting dial provided on the camera body. The user may rotate the view-setting dial to switch the focus area displayed and superposed in the viewfinder, from one to another. In other words, the focus area can be switched from one to another as the view-setting dial is rotated. Therefore, the user can recognize, by intuition, the switching of focus area points in association with the when rotating of the view-selecting dial.
The camera disclosed in Jpn. Pat. Appln. No. 6-201984 can detect the line of sight of the user who is observing the image in the view viewfinder and can select the focus area that aligns with the direction of the line of sight.